. >> and now for the moment we have all been waiting for. >> first lady michelle obama gave the oscars a jolt of excitement and a huge surprise when she appeared from the white house to announce the night's biggest prize, best picture. >> and the oscar goes to -- "argo." >> reporter: it was an especially sweet victory for ben affleck, who wasn't even nominated for directing the iranian hostage thriller. >> i think everyone in the movie, op the movie, worked on the movie, did anything with this movie. >> reporter: life of pi, based on the best-selling novel about a boy adrift at sea with a tiger, won the most oscars, four, including best director for ang lee. >> thank you, academy. namaste. >> reporter: he played one of the greatest presidents in history, and "lincoln's" actor daniel day lewis, had a first of his own. winning three oscars. >> i'm so grateful. >> reporter: she took a tumble heading to the stage, but everyone else was on their feet when "silver linings playbook" jennifer lawrence won for best actress. >> you guys are standing up because you feel bad i fell, and that's really emb